Function
lerp
Common
```kotlin
fun lerp(start: ScaleFactor, stop: ScaleFactor, fraction: Float): ScaleFactor
```
Linearly interpolate between two `ScaleFactor` parameters
The `fraction` argument represents position on the timeline, with 0.0 meaning that the
interpolation has not started, returning `start` (or something equivalent to `start`), 1.0
meaning that the interpolation has finished, returning `stop` (or something equivalent to
`stop`), and values in between meaning that the interpolation is at the relevant point on the
timeline between `start` and `stop`. The interpolation can be extrapolated beyond 0.0 and 1.0, so
negative values and values greater than 1.0 are valid (and can easily be generated by curves).
Values for `fraction` are usually obtained from an `Animation`, such as an
`AnimationController`.